Surgeons operating on human patients often experience some difficulty in properly identifying tissue structures. If the wrong tissue structure is cut, the patient may suffer serious or even deadly consequences. This is a significant concern when surgery is performed proximate to the ureters. Because patients often have unique anatomy and because of the similarity in appearance of a ureter with other tissue structures, especially when viewed using laparoscopic instruments, inadvertent ureter dissections occur too frequently. What is therefore needed is a device that can easily and accurately alert the surgeon to the presence of a ureter, even when the ureter is not visually or otherwise identifiable by the surgeon.